Abrasive device



Oct. 2, 1951 H. UQGALLAGHER ABRASIVE DEVICE Filed Dec. 29, 1949 farPatented Oct. 2, 1951 UNITED STATES PATENT OFFICE ABRASIVE DEVICE harryIT. Gallagher, Chicago, Ill.

Application December 29, 1949, Serial No. 135,685

claims. (01; 51-109) 1 This invention relates to an abrasive device,and-more particularly to a.--rotar ;abrasive device for use in preparingthe edges. of instruments such asthose made of high-grade surgicalsteel,

as for example, those used by dentists andchiropodists.

A feature of this invention is to provide a new and improvedabrasive'device of the character described. s p

Another feature is the provision of a rotary abrasive wheel having aworkingsurface on its side to provide an effective diameter of Workingsurface larger than the diameter of the wheel itself.

Another feature is the provision of a device 'offjthe characterdescribed in which a side working surface on an abrasive wheelisaccessible for abradin'g the edge of an instrument from either side ofthe Working surface without interference from other parts of the wheel.7

Another feature is the provision 'of a relatively small diameterabrasive wheel having a side working surface having an effectivediameter much larger than that of the wheel, yet requiring lesspower tooperate than astraightwheel of said effective diameter.

Another feature is that the side working surface provides a. greaterwid-th of'working surface fora wheel of a given thickness and amount ofabrasive material.

A further feature is theprovision ofrrotary abrasivewheels having'aworking surface on the side of the wheel corresponding in radial" crosssection to the cutting edge ofthe instrument toabeabraded.

Other features and advantages will be apparent from the description of aparticular embodiment of the invention illustrated 'in the accompanyingdrawings, in which:

Fig. 1 is an 'elevatio'mpartly in "section, illustrating an embodimentof this invention;

Fig. 2 is a Fig. 1';

Fig. 3 is a vertical cross section throughwan abrasive wheel showingauvaried. form of working "surface'thereon; and

planvi'ew of the device illustrated in cal instrument such as used bydentist's or chiropodists, it is preferred that the diameter of theabrasive wheel be such that the cutting edge of the instrument is nottoo deeply hollow-ground. Ordinarily, a straight wheel, that is oneinwhich the abrasive surface is around the periphery of the wheelgenerally normal to the sides ofthe wheel, is used to sharpen suchinstruments. It will be readily understood that'with a decrease indiameter of such a straight wheel an increase in the amount of hollowgrinding of the cuttin ed'ge of the instrument results, as does alsoanincrease in the amount of tearing or gougingfof the edge because ofthe angle of attack of the Wheel to the edge being too great. Also witharelatively large diameter Wheel more power is required to operate thewheel than is necessary with amuch smaller diameter wheel. N

This invention has provided a solution to the above difiiculties whereina relatively smalldiameter wheel may be used effectively and easilytoabrade the instruments of the'pra'ctitioner' and the device may beplaced in his oflice tahing'up relatively small space and utilizing: arelatively small amount of power in its operation. The term abrade orabrasive as herein used is to be construed as meaning any operationcharacterized by the act of a wearing by-friction; which may for examplebe any of the operations-commonlyn-called honing, sharpening, polishing,shapingQbuffi-ng; or the like.

The embodiment illustrated in Figs. l -and Z comprises generally-ahousing 10 having a-bottomll supporting the housing and a top plate l2enclosing at least a portion of the abrasive wheel all of relativelysmall size so that the dentist, chiropod-ist or other user may place thedevice at some convenient location where he may" use it at any time toabrade the cutting edges of his instruments. Mounted within the housing10 isa slanting support member I3 carrying a motor 14 by brackets I5.The motor I4 is operativelyconnected to a shaft 16 upon which theabrasive wheel 20 is securely mounted and is preferablya relatively slowspeed motor, that is havingpa speed of between and 200 revolutionsperminute. The support member 13 is inclined within the housing [0 aswill hereinaftermore lfully ap- .pear.

' diameter.

3 general known structures having an abrasive material bonded togetherto make a homogenous wheel or it may be of any base composition havingan abrasive surface secured thereto, as a coating, disk, or the like.The wheel 2|] has a working surface 2| on its side adjacent the pe-.riphery 22 of the wheel and facing away from the plane of the wheel atapproximately 10 degrees and the shaft I6 upon which the wheel ismounted is inclined within the housing at the same angle to the verticalso that the working surface 2| at the upper left hand portion of thewheel lies in a horizontal plane.

In providing a working surface on the side of the wheel and incliningthe Wheel, an effective diameter at the abrading position will be muchlarger than the diameter of the wheel itself. As an example, a wheelhaving a diameter of approximately 6' inches and a working surface at 15degrees to the plane of the wheel, would have at an abrading position aneffective are of working surface corresponding to the arc of a straightwheel approximately 14 inches in diameter. This would correspond tohavinga straight wheel of a diameter of about 14 inches and wouldrequire, as will be readily understood, a much greater power unit tooperate than the 6 inch wheel utilizing the side working surfacedisclosed by this invention. A working surface on a 6 inch diameterwheel inclined at 10 degrees to the plane of the wheel would have astill larger effective Also a greater width of working surface-may behad with the working surface on the side of the wheel than with the samediameter of straight wheel using the same amount of material in thewheel.

top plate |2 provides a shield about the abrasive wheel protecting thefingers and hands of the operator. It will be noted that the top |2 hasan opening 3| corresponding in configuration to an arcuate segment ofthe working surface 2| so that only a portion of the wheel projectsabove the level of the top l2. A ledge 32 beyond the outer periphery ofthe wheel, comprising an ex- 5';-

4 be sharpened by holding the handle of the blade over the ledge 32 ofthe top I2. In order to sharpen the other side of the blade the blade isturned over and the handle held over the center portion of the wheel sothat the working surface may come into the cutting edge from the samedirection as when sharpening the other side, the center depression inthe wheel permitting a low enough mounting of the guard plate to avoidinterference with the handle of the instrument. As will readily be seenfrom Figs. l and 2 the top |2 covers most of the wheel so that the handof the operator would not be injured while holding the handle of theinstrument generally over the center of thewheel in performing anabrading operation.

Many dentaland chiropody instruments have a curved cutting edge ratherthan a straight one. When it is desired to sharpen such an instrument,an abrasive wheel I29, such as illustrated in Fig. 3, may be providedwith a working surface |2l generally at a small angle to the plane ofthe wheel and curved along a radial In mounting the abrasive device inthe housing In as described above, the

in sharpening an instrument because the handle of the instrument may beheld on either the left hand or right hand side of the wheel withoutinterference with the wheel itself. When the working surface is on theside of the wheel as in the present invention, ordinarily the workingsurface may only be approached from outside of the wheel. In the presentinvention the working surface 2| may be approached from either "sidethereof. For example, one side of the blade may cross section tocorrespond to the cutting edge of the instrument to be sharpened. Thewheel I20 may be substituted for the wheel 20 in the device illustratedin Figs; 1 and 2 by simply removing the top l2 on the housing it,loosening the nut 35 which retains the wheel 20 on the shaft i6 and thenplacing the wheel I20 in position on the shaft. 1

In Fig. 4 another wheel 22|Jis illustrated having a working surface 22|with annular grooves 222 in the working surface. Such a wheel may beused for sharpening instruments having a hooked portion and instrumentswith rounded cutting edges such as nucleus knives used by chiropodists.Other wheels having various shaped working surfaces may be provided asdesired. 7

From the foregoing it is believed that this invention provides a new andimproved abrasive device in which a relatively small diameter abrasivewheel may be used to obtain a requisite larger diameter effectiveworking surface and which requires substantially less power to operatethan a straight wheel having said effective working diameter.

While I have herein described certain embodiments of my invention, it isapparent that some changes may be made by those skilled in the art.However, the invention is not to be limited by the foregoing descriptionbut rather to be construed broadly within the spirit and scope of theappended claims.

Iclaim: V 1, A rotary abrasive device comprising: a housing including aplanar work supporting surface, said surface having an arcuate openingtherein; a shaft supported adjacent said surface and at an angle of lessthan 30 degrees to a perpendicular to said surface; power meanssupported by said housing for rotating the shaft; an abrasive wheelmounted on the upper endof said shaft at substantially degrees .to-said'shaft; said wheelhaving anannular radial abrasive face surfacepositioned at an angle of less than 30 degrees to the'plane normal tothe axis ofrotation of said wheel andthe same as the first mentionedangle, withthe surface facing away from said shaft anda'depressedportionin the center of said wheel adjacent said abrasive surface, saidinclination. of said shaft being sufficient to rotate successiveportions of the abrasive surface into 5 face and extending through saidarcuate opening, with the work support surface masking the remainder ofsaid abrasive surface and the corresponding portions of said depression.

2. A device of the character claimed in claim 1, 5 wherein the angle ofthe shaft with respect to the perpendicular and the angle of theabrasive face surface with respect to the plane normal to the axis ofrotation of the wheel are both between 10 and 15 degrees, and both thesame angle.

HARRY U. GALLAGHER.

REFERENCES CITED The following references are of record in the 15 fileof this patent:

Number UNITED STATES PATENTS Name Date Howson Apr. 8, 1879 Barclay Feb.12, 1884 Conradson Jan. 26, 1892 Brown Mar. 13, 1900 Connet June 29,1909 Redden Feb. 3, 1914 Barnhart Oct. 25, 1921 Osterholm May 7, 1935Weidrich Nov. 2, 1937 Myers Apr. 19, 1938 Benedict Mar. 19, 1940 AtkinAug. 2, 1949

